content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.observable.internal.operators;
  
  import java.util.concurrent.atomic.AtomicReference;
  
  import io.reactivex.common.*;
  import io.reactivex.common.annotations.Nullable;
  import io.reactivex.common.disposables.CompositeDisposable;
  import io.reactivex.common.exceptions.Exceptions;
  import io.reactivex.common.functions.Function;
  import io.reactivex.common.internal.disposables.DisposableHelper;
  import io.reactivex.common.internal.functions.ObjectHelper;
  import io.reactivex.common.internal.utils.AtomicThrowable;
  import io.reactivex.observable.*;
  import io.reactivex.observable.internal.observers.BasicIntQueueDisposable;
  
  /**
   * Maps a sequence of values into CompletableSources and awaits their termination.
   * @param <T> the value type
   */
  public final class ObservableFlatMapCompletable<T> extends AbstractObservableWithUpstream<T, T> {
  
      final Function<? super T, ? extends CompletableSource> mapper;
  
      final boolean delayErrors;
  
      public ObservableFlatMapCompletable(ObservableSource<T> source,
              Function<? super T, ? extends CompletableSource> mapper, boolean delayErrors) {
          super(source);
          this.mapper = mapper;
          this.delayErrors = delayErrors;
      }
  
      @Override
      protected void subscribeActual(Observer<? super T> observer) {
          source.subscribe(new FlatMapCompletableMainObserver<T>(observer, mapper, delayErrors));
      }
  
      static final class FlatMapCompletableMainObserver<T> extends BasicIntQueueDisposable<T>
      implements Observer<T> {
          private static final long serialVersionUID = 8443155186132538303L;
  
          final Observer<? super T> actual;
  
          final AtomicThrowable errors;
  
          final Function<? super T, ? extends CompletableSource> mapper;
  
          final boolean delayErrors;
  
          final CompositeDisposable set;
  
          Disposable d;
  
          volatile boolean disposed;
  
          FlatMapCompletableMainObserver(Observer<? super T> observer, Function<? super T, ? extends CompletableSource> mapper, boolean delayErrors) {
              this.actual = observer;
              this.mapper = mapper;
              this.delayErrors = delayErrors;
              this.errors = new AtomicThrowable();
              this.set = new CompositeDisposable();
              this.lazySet(1);
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              if (DisposableHelper.validate(this.d, d)) {
                  this.d = d;
  
                  actual.onSubscribe(this);
              }
          }
  
          @Override
          public void onNext(T value) {
              CompletableSource cs;
  
              try {
                  cs = ObjectHelper.requireNonNull(mapper.apply(value), "The mapper returned a null CompletableSource");
              } catch (Throwable ex) {
                  Exceptions.throwIfFatal(ex);
                  d.dispose();
                  onError(ex);
                  return;
              }
  
              getAndIncrement();
  
              InnerObserver inner = new InnerObserver();
  
              if (!disposed && set.add(inner)) {
                  cs.subscribe(inner);
              }
          }
  
          @Override
          public void onError(Throwable e) {
              if (errors.addThrowable(e)) {
                  if (delayErrors) {
                      if (decrementAndGet() == 0) {
                          Throwable ex = errors.terminate();
                          actual.onError(ex);
                      }
                  } else {
                      dispose();
                      if (getAndSet(0) > 0) {
                          Throwable ex = errors.terminate();
                          actual.onError(ex);
                      }
                  }
              } else {
                  RxJavaCommonPlugins.onError(e);
              }
          }
  
          @Override
          public void onComplete() {
              if (decrementAndGet() == 0) {
                  Throwable ex = errors.terminate();
                  if (ex != null) {
                      actual.onError(ex);
                  } else {
                      actual.onComplete();
                  }
              }
          }
  
          @Override
          public void dispose() {
              disposed = true;
              d.dispose();
              set.dispose();
          }
  
          @Override
          public boolean isDisposed() {
              return d.isDisposed();
          }
  
          @Nullable
          @Override
          public T poll() throws Exception {
              return null; // always empty
          }
  
          @Override
          public boolean isEmpty() {
              return true; // always empty
          }
  
          @Override
          public void clear() {
              // nothing to clear
          }
  
          @Override
          public int requestFusion(int mode) {
              return mode & ASYNC;
          }
  
          void innerComplete(InnerObserver inner) {
              set.delete(inner);
              onComplete();
          }
  
          void innerError(InnerObserver inner, Throwable e) {
              set.delete(inner);
              onError(e);
          }
  
          final class InnerObserver extends AtomicReference<Disposable> implements CompletableObserver, Disposable {
              private static final long serialVersionUID = 8606673141535671828L;
  
              @Override
              public void onSubscribe(Disposable d) {
                  DisposableHelper.setOnce(this, d);
              }
  
              @Override
              public void onComplete() {
                  innerComplete(this);
              }
  
              @Override
              public void onError(Throwable e) {
                  innerError(this, e);
              }
  
              @Override
              public void dispose() {
                  DisposableHelper.dispose(this);
              }
  
              @Override
              public boolean isDisposed() {
                  return DisposableHelper.isDisposed(get());
              }
          }
      }
  }
  